U.S. patent application number 10/585520 was filed with the patent office on 2009-12-17 for optical sensor device having a lens system at least partially integrated into the unit housing.
Invention is credited to Steffen Abraham, Hans-dieter Bothe, Heiko Freienstein.
Application Number | 20090309026 10/585520 |
Document ID | / |
Family ID | 34716406 |
Filed Date | 2009-12-17 |
United States Patent
Application |
20090309026 |
Kind Code |
A1 |
Bothe; Hans-dieter ; et
al. |
December 17, 2009 |
Optical sensor device having a lens system at least partially
integrated into the unit housing
Abstract
An optical unit, having a sensor device in particular, including
a housing enclosing same, a radiation-sensitive sensor surface,
designed for detecting electromagnetic radiation from a frequency
section, having a predefined width and position, of the spectral
range including the near infrared range and/or the visible range,
and a lens system. In order to reduce the cost and complexity for
mounting a lens on the housing and to obtain a uniform housing
surface on the object side, a part of the lens system acting as a
lens on the object side or the entire lens system of the unit is
designed as an integral component of the housing of the unit.
Inventors: |
Bothe; Hans-dieter; (Seelze,
DE) ; Freienstein; Heiko; (Weil der Stadt, DE)
; Abraham; Steffen; (Hildesheim, DE) |
Correspondence
Address: |
KENYON & KENYON LLP
ONE BROADWAY
NEW YORK
NY
10004
US
|
Family ID: |
34716406 |
Appl. No.: |
10/585520 |
Filed: |
November 12, 2004 |
PCT Filed: |
November 12, 2004 |
PCT NO: |
PCT/EP2004/052947 |
371 Date: |
May 13, 2009 |
Current U.S.
Class: |
250/338.1 ;
250/552; 359/811 |
Current CPC
Class: |
G02B 7/021 20130101;
G02B 9/06 20130101; H04N 5/2254 20130101 |
Class at
Publication: |
250/338.1 ;
250/552; 359/811 |
International
Class: |
H01L 31/02 20060101
H01L031/02; G02B 7/02 20060101 G02B007/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 9, 2004 |
DE |
10 2004 001 425.6 |
Claims
1-12. (canceled)
13. An optical functional unit comprising: an optical functional
element; a housing enclosing the optical functional element; and a
lens system, the optical functional element operating with the lens
system, wherein one of (a) an object-side part of the lens system
acting as an optical lens and (b) the entire lens system of the
unit is an integral component of the housing of the unit.
14. The unit according to claim 13, wherein the unit is a sensor
device and the functional element includes a radiation-sensitive
sensor surface, which is designed to detect electromagnetic
radiation from a frequency section of the spectral range including
at least one of a near infrared range and a visible range, the
frequency section having a predefined width and position.
15. The unit according to claim 13, wherein the unit is a subunit
for use in a passenger compartment of a motor vehicle.
16. The unit according to claim 13, wherein the one of (a) the part
of the lens system acting as an optical lens and integrated into
the housing and (b) the entire lens system integrated into the
housing is transparent to a frequency section, whose position and
width are predetermined, and which is of electromagnetic radiation
from a near infrared range, and is opaque to a visible range.
17. The unit according to claim 13, wherein a housing part
containing at least part of the lens system is made using injection
molding technology.
18. The unit according to claim 13, wherein a housing part
containing at least part of the lens system is part of an interior
lining of a motor vehicle.
19. The unit according to claim 13, wherein the functional element
includes an artificial light source.
20. The unit according to claim 19, wherein the light source is a
light emitting diode.
21. The unit according to claim 19, wherein the light source is a
diode emitting infrared light.
22. A housing for an optical unit comprising: a housing unit
enclosing an optical functional element, the optical functional
element operating with a lens system, wherein one of (a) an
object-side part of the lens system acting as an optical lens and
(b) the entire lens system is an integral component of the housing
unit.
23. A range video system comprising an optical sensor device, the
optical sensor device including: an optical functional element; a
housing enclosing the optical functional element; and a lens
system, the optical functional element operating with the lens
system, wherein one of (a) an object-side part of the lens system
acting as an optical lens and (b) the entire lens system of the
device is an integral component of the housing of the device.
24. The range video system according to claim 23, wherein the
system is used in a motor vehicle.
25. A camera system comprising an optical sensor device, the
optical sensor device including: an optical functional element; a
housing enclosing the optical functional element; and a lens
system, the optical functional element operating with the lens
system, wherein one of (a) an object-side part of the lens system
acting as an optical lens and (b) the entire lens system of the
device is an integral component of the housing of the device.
26. The camera system according to claim 25, wherein the camera
system is a stereo camera system.
27. The camera system according to claim 25, wherein the system is
used in a motor vehicle.
Description
FIELD OF THE INVENTION
[0001] The present invention is directed to an optical functional
unit, including an optical functional element operating with a lens
system and a housing enclosing same.
BACKGROUND INFORMATION
[0002] Such units, in the form of an optical sensor device having a
sensor surface and a lens system, for example, are known from the
field of automobile technology. A sensor device is referred to as
optical when it detects electromagnetic radiation from a frequency
section of the visible (VIS) and/or the near infrared (NIR)
spectrum range. The wavelengths of the radiation are approximately
between 400 nm to 1,000 nm. Another example of such units is light
fixtures having a light source, the light of which is emitted via a
special lens system.
[0003] Optical sensor devices are used in a wide range of
technology fields. Optical sensor devices are being used more
frequently in motor vehicles in particular. They are used, for
example, for detecting the surroundings or for sensing the
passenger compartment of a motor vehicle.
[0004] An important component of an optical sensor device is its
lens system acting as its "eye." The radiation enters through the
lens system and is refracted or focused according to the intended
imaging conditions. The lens system is essentially made up of one
or multiple lenses. In most of the presently known optical sensor
devices, the lens system is a self-contained closed part which is
mounted on or on the front of the housing of the sensor device.
Appropriate mounting devices on the housing, such as threaded
holders, are necessary for holding the lens system. The manufacture
of the individual parts of the lens system and their connection to
the housing of the sensor device entail additional complexity and
expenditure. The lens systems protrude to the outside in most cases
and are therefore conspicuous from the outside to the viewer. Edges
and recesses in the unit housing are created due to the necessary
apertures for the lens system. Dirt which tends to accumulate at
these points is not able to be easily removed from these points.
However, sensor devices are known in which the lens system does not
protrude to the outside, but is situated behind a glass pane and is
protected from outside effects. Known are, for example,
configurations of optical sensor devices behind rear windows or, as
described in Japanese Patent No. JP 03-273953, behind the glass of
the headlights of a motor vehicle. However, an additional glass
pane is used which is not a necessary component of the lens system.
This results in additional complexity and higher costs. Moreover,
each additional medium in the optical radiation path has an adverse
effect on the image quality of the sensor device due to
reflections, absorptions, and diffraction.
[0005] The sensor device described in German Patent Application No.
DE 198 05 000 represents an improvement over the related art. The
lens system or parts thereof are integral components of the
windshield. The housing is situated directly behind the windshield.
However, this particular design of the windshield including
integrated lenses incurs great costs, and mounting the sensor
housing on the flat pane is problematic.
SUMMARY OF THE INVENTION
[0006] The present invention provides units in terms of more or
less compact function units, including, for example, a
multi-purpose optical sensor device or a light fixture in which the
particular lens system is inserted into the self-contained closed
unit in a simple and cost-effective manner. At least one optical
lens on the object side, as a separate single part, and its
mounting device are no longer necessary. For the present invention,
a lens is considered optical when it acts as a lens for radiation
from the VIS and/or NIR range.
[0007] The uniform housing surface on the object side according to
the present invention is easy to clean and offers sufficient
contamination protection. An interfering protrusion of the lens
system is avoided. An additional pane in front of the lens system,
which impairs the optical quality, is unnecessary.
[0008] According to an advantageous embodiment of the present
invention, the sensor device is designed for use in a motor vehicle
for monitoring the passenger compartment. In particular in motor
vehicles, the optical sensor devices according to the present
invention may be installed simply and cost-effectively in a manner
which does not subsequently irritate the driver.
[0009] According to another advantageous embodiment of the present
invention, the part of the lens system, integrated into the housing
and acting as an optical lens, or the entire lens system,
integrated into the housing, is designed to be transparent for the
NIR range and non-transparent for the VIS range for a frequency
section of the electromagnetic radiation, predefined with respect
to position and width. Images of objects illuminated by radiation
from the NIR range and those from the VIS range are very similar.
The absorption and reflection behaviors do not show any important
differences. A space may thus be monitored via video using NIR
radiation alone. Due to the fact that the lens system is
non-transparent to the human eye, sensing may occur without the
observed person being aware of it and feeling disturbed. From the
outside, the person sees a uniform, non-transparent housing
surface.
[0010] According to another, improved embodiment of the sensor
device according to the present invention, the housing part, at
least partially including the lens system, is manufactured using
injection-molding technology. This is a particularly simple and
cost-effective way to further reduce the complexity and costs for
manufacturing and integrating the lens system in particular.
[0011] Another advantageous embodiment of the present invention
provides for the design of the housing part, at least partially
including the lens system, to be a component of an interior lining
of a motor vehicle, thereby making the units what is referred to as
"sub-units." This eliminates manufacturing costs for both the
interior lining and the housing part of the sensor device on the
object side. The lens system of the device according to the present
invention is integrated into the interior lining without protruding
conspicuously and is not noticed in a disturbing way by the
vehicle's passengers. This design advantageously allows
cost-effective and inconspicuous sensing of the vehicle's passenger
compartment, e.g., for controlling restraint systems.
[0012] The sensor device according to the present invention is
particularly suitable for using video to monitor systems, such as
range video systems and camera systems, particularly spatially
detecting stereo camera systems. Such systems are particularly well
suited for use in motor vehicles.
[0013] Such camera systems often require their "own," "active"
lighting, which is frequently sensibly integrated into the camera.
In order for the light source to optimally light the scene (or
section of the scene), an appropriate lens system, made up of one
or multiple optically acting lenses, may be mounted in front of the
light source, according to the present invention. The light source
may be light bulbs, for example, or LEDs, laser diodes, or IREDs
(IR emitting diodes) which are associated with other advantageous
effects. The enclosure according to the present invention may also,
according to a simple variant, have no optical effect and may
simply be used for protecting and concealing the light source. In
other words, the housing may not only be used as an optically
acting part of the lens system in front of an image recorder, but
may also be used, alone or in connection with other optical
functional elements, as an optically acting or merely as a
concealing part in front of the light source. That is, the light
source as a first optical functional element may also be situated
in the same housing as the sensor device as a second optical
functional element.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 shows a schematic cross section of an exemplary
embodiment of the optical sensor device according to the present
invention.
[0015] FIG. 2 shows a cross section of a part of the housing,
acting as an optical lens, of an exemplary embodiment of the sensor
device according to the present invention.
[0016] FIG. 3 shows a schematic representation of an exemplary
application of a video-based system including the optical sensor
device according to the present invention.
DETAILED DESCRIPTION
[0017] FIG. 1 shows a schematic cross section of an example of
optical sensor device 1 according to the present invention. Optical
sensor device 1 is enclosed by a unit housing 5. This housing 5 is
made up of molded parts via injection molding, for example.
Manufacture in a different way is likewise possible. According to
the present invention, unit housing 5 has a lens-shaped convexity 3
on the object side. It is part of the lens system of sensor device
1 including an additional lens 9. The lens system is not
necessarily made up of two parts acting as lenses, but may be
designed differently as a function of the optical requirements and
to include one or multiple optical elements. With a particular
further design, lens-shaped convexity 3 of unit housing 5 may be
sufficient as a lens system for an appropriate use of sensor device
1.
[0018] According to the present invention, in particular in the
area of lens-shaped part 3, unit housing 5 is made of a material
which is transparent for electromagnetic radiation in a frequency
range for NIR and/or VIS. Dyed plexiglass or a polycarbonate dyed
for injection molding are preferable, for example. These materials
are non-transparent to the human eye, but are transparent for
radiation from the NIR range, so that the observer regards housing
5 as a common unit cover. The incident radiation is focused by lens
system 3, 9 onto the side of sensor surface 11 which is sensitive
to this radiation. Starting from an object point 13, a beam path is
indicated by dashed lines. Sensor surface 11 is a CCD chip
sensitive to NIR radiation, for example. The image information
recorded by sensor surface 11 is conveyed in electronic form to
image-processing or imaging system components via signal line 15,
as is known from the related art.
[0019] In order to shield sensor surface 11 from radiation which
penetrates housing 5 outside of lens-shaped convexity 3, housing 5
is provided on the inside with a shield 17 in these areas. This
shield 17 is made of a material which is impermeable for radiation
from the frequency range to which sensor surface 11 is
sensitive.
[0020] Furthermore, a filter 19 is situated in the beam path
between lens system 3, 9 and sensor surface 11. This filter is
permeable only for radiation from a predefined, tightly limited
frequency band in the NIR range, for example. TiO2 is used as the
filter material, for example, which has a permeable frequency
window of 40 nm band width in the NIR range.
[0021] FIG. 2 schematically shows a cross section of a part 3 of
housing 5, acting as an optical lens, as an example of optical
sensor device 1 according to the present invention. Housing 5 is
transparent for NIR radiation. It is spherically convex in center
section 3 on the object side. On the inside in comparison, housing
5 is only slightly convex in this section 3 in the direction of the
object, so that the diameter of the housing wall increases toward
the center. This part 3, acting as an optical lens, forms a lens
which is suitable for wide angle shooting. Optical axis 21 runs
perpendicular to the surface of housing 5 through the center of
section 3 designed as a lens. Auxiliary edge 7, which encloses
section 3 from the inside, is used for connecting additional
elements of the lens system or other components of the sensor
device at a fixed distance.
[0022] FIG. 3 shows a schematic representation of a video-based
system, which includes optical sensor device 1 according to the
present invention, for monitoring the passenger compartment of a
motor vehicle 25. This monitoring is used for controlling restraint
systems such as airbags.
[0023] The passenger compartment of motor vehicle 25 is lighted by
an NIR lamp 27. This is, for example, a field of LEDs emitting in
the NIR range. The passenger compartment of the motor vehicle,
lighted in this way, is recorded by a recording system which
includes one or multiple optical sensor devices 1 which are
sensitive to this frequency range. The recording system detects the
objects in the passenger compartment of the motor vehicle
three-dimensionally and is designed as a range video system or a
stereo camera system, for example.
[0024] The part of the housing of optical sensor device 1 including
the lens system on the object side preferably forms a part of the
interior lining of motor vehicle 25. Sensor device 1 is connected
to a control unit 29 of the recording system. Control unit 29
regulates the functions, which primarily include the alignment and
the sensitivity of sensor device 1, and receives the image signals.
It is connected to control unit 31 of the restraint system. This
analyzes the transmitted image data with regard to type, position,
and distance of the object in front of airbag 33. If, in the event
of an accident, for example, no living object is detected in front
of airbag 33, control unit 31 does not trigger the airbag. However,
if a person is situated in the seat in front of airbag 33, the
airbag is triggered more or less powerfully depending on the
distance of the person from the deployment range of the airbag. If
the person is situated very close to the deployment range,
triggering of airbag 33 is attenuated. This reduces the risk of
injury when the airbag is triggered.
[0025] Although the present invention is described above on the
basis of preferred exemplary embodiments, it is not restricted
thereto, but is modifiable in numerous ways.
[0026] The optical sensor device according to the present invention
may be used in banks for surveying the teller area, for example.
The customer does not recognize the optical sensor device as such
and is not disturbed by the camera surveillance.
* * * * *